Marjorie - the OSHA Methylene Chloride standard (29CFR 1910.1052) requires initial monitoring for employees when it is to be used in the workplace. While students aren't covered by the standard, you and other employees are. You are absolutely right that it should be handled exclusively in a hood, but that doesn't negate the requirement for monitoring; I suspect many colleges aren't aware of this requirement. I would urge you to get the monitoring done and use that as ammunition to restrict use of methylene chloride to the chemical hood.

I have a question for anyone involved in undergraduate Organic Chemistry labs.

Methylene chloride is listed as a recognized carcinogen in California, and it is a B2 probable human carcinogen. As you all know, it is a volatile liquid commonly used in undergraduate Organic Chemistry labs as the organic solvent in liquid-liquid extractions using a separatory funnel. As many OChem labs lack adequate fume hoods, many colleges do these extractions at the bench, and so are venting methylene chloride in the general laboratory. Generally, these are not microscale extractions, but are regular lab scale with a 250 or 500 mL sep funnel.

It is a volatile probable human carcinogen and thus I believe that it should be handled in the fume hood and the extraction should also be done in a fume hood. Do you agree or disagree? If you agree, have you been successful in changing how your department handles methylene chloride in undergrad labs, and if so, how did you successfully argue your case to handle it in fume hoods?

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